Such a devices is known, for example, from DE 198 46 220 A1. Virtually any conventional electric motor which has a housing or is installed in a larger device has such a design.
In the context of mobile applications, the power-to-weight ratio of electric motors is very important. In particular, attempts are made to reduce the weight of the electric motors as much as possible. It is desirable to reduce weight both in the case of the so-called active parts (i.e. the electromagnetically active components, i.e. magnets and windings and laminations or laminate stacks) and in the case of the remaining components, the so-called passive parts.
Attempts are generally made in the past to optimize the individual components of the systems. However, a particularly high degree of potential lies in integrative lightweight construction, for example by structural and functional integration of active and passive parts.